Process of joining metal pieces.



No. 717,840. PATENTED JAN. 6,. 1903.

-H.- GOLDSGHMIDT.

. PROCESS OF JOiNING METAL PIECES.

APPLICATION FILED J N 19. 1901.

I0 KODBL. 2 SHEETS-SHEET -1-,

7 66629601 fiz/vcntor':

110,717,840. 'PATENTEDJAN. 6, 1903.

I H. GOLDSOHMI-DT. PROCESS OF JOININGiMETALPIEGES. APPLICATION FILEDJUI-TE 19,1901.

. no MODE-L. 2 sums-sum a hole does not directly flow upon the rails,but

UNITED STATES PATENT OFFICE.

CLARENCE B. SCHULTZ,

OF BERLIN, GERMANY.

PROCESS OF JOINING METAL PIECES.

SPECIFICATION forming part of Letters Patent No. 717,840, dated January6, 1903.

Application filed .Tune 19, I901- To a. whom it may concern:

Be it known that I, HANS GOLDSCHMIDT, a subject of the King of Prussia,German Emperor, and a resident of Essen-on-the-Ruhr, Germany, haveinvented anew and Improved Process of Joining Metal Pieces, of which thefollowing is an exact specification.

My invention relates to a new and improved process for joining metalpieces. In the proc- 'csses known up to date for joining metal pieces bywelding the same with the aid of the heat produced by the chemicalreaction between aluminium and oxids of metals or otheroxygen-containing metal compounds (especially oxid of iron) the reactionmass is used only as calorifying agent and the metal produced by thereaction serves only as a heatconductor. Therefore in thesealumino-thermo processes care was taken that the molten alumina-slag atfirst came incontact with the pieces to be welded and only after thesame had formed a protecting-coating around the pieces the molten metalwas flown around the Welding-pieces. In the most cases this successiontook place already by the mere casting of the reaction mass out of thecrucible or melting-pot, as naturally at firstthe alumina floating aboveflows out and afterward the metal. Hereby itwas avoided that the moltenmetal could come in direct contact with the molten pieces to be weldedand that this metal could join with the metal pieces.

By my new process it is attained that the molten metal comes directly incontact with the welding-pieces, so that the metal. may partly join withthe pieces, thereby strengthening the joints, whereafter the wholereaction mass begins its operation as calorifying agent forthe weldingprocess.

The process shall be described,'for example, as used for joining railsor the like.

The joining faces of the rails are at first surrounded with a suitablemold manufactured of iron-sheet, clay, or the like, whereafter acrucible provided with a tap-hole is placed over this mold in that waythat the stream of the molten mass flowing'out of this flows into thespace between the rails and the wall of the mold. Then this crucibleafter Serial No. 65,192. (No model.) i

closing the tap-hole is filled with-the reaction mixture-for instance, amixture of aluminium and oxid of ironwhereafter the reaction isintroduced. Once the reaction being in progress further quantities ofthe mixture may be added. When the whole mass is in reaction, thetap-hole is opened, so that at first the molten highly-overheated iron,and afterward the molten alumina floating above the iron, flows into themold. The iron forms a layer around the lower flange of the rails andeffects the joining of the touching faces on this lower part. Thealumina flowing out after the iron has a double effect upon the piecesto be joined. First, the heating attained by the same may effect thewelding of the joining faces; secondly, the heating of the upper partiofthe rails prevents the bending up of the rails near the joining faces,which bending up was tried to be done away with until now in similarprocesses by holding the joining faces down by means of clamps and thelike.

The tap-hole of the crucible may be closed by means of a clay plug orthe like, or the hole may be covered with a metal sheet, (ironsheet,)asbestos, or the like before filling the crucible with the mixture. Inthis case the molten iron as soon as the reaction has come to the bottomof the crucible will melt this covering, whereby the tap-hole will beopened automatically.

In order to make my invention more clear, I willproceed to illustratethe process by an example described at the hand of the accompanyingdrawings, in which similar letters denote similar parts, and in which-Figure 1 shows a section through one of the two rails to be joined andthe mold. Fig. 2 is a side view of the rails. Fig. 3 is a perspectiveview of the joint. Figs. 4, 5, 6, 7, 8, 9, and 10 are modified forms ofarrange ments for carrying the process into effect.

' In Figs. 1 and 2, a a are the rails to be joined. I) b are iron-sheetmolds, the upper one of which consists of two parts surrounding therails near the joining faces. The side walls 0 c of these molds mayadvantageously be formed of sand or wet clay. By the specialconstruction of the molds three hollow manner: Themetal pieces arepressed against each other in such a manner that a displacement duringthe heating of the pieces by means of the reaction mass is renderedimpossible. Then a crucible is filled with a mixture of aluminium andoxid of iron, both in pulverized form, whereafter the mixture isinflamed. cible beforehand with a small quantity of the mixture, then toinflame the same and gradually add further quantities. \Vhen the wholemass is in reaction, the molten alumina floating above the iron is castinto the form f f. This aluminaslag congeals at once upon the coldsurfaces of the rails and the bottom as well as the side walls of themold and forms coatings d 't', which protect the top part of the railsagainst getting deformed. The other part of the alumina-slag between thecoatings is still liquid, but congeals also by and by. Then the iron iscast into the mold b after a hole 0 has been punched through the bottomof the mold b and the alumina coating 7}. Evidently the bottom of themold b will not offer great resistance to punching the hole through,since the metal has been heated by the alumina.

As already mentioned, the alumina has the purpose to heat the two partsto be welded together, while the iron shall form a rail-fish around thebottom parts of the two rails in order to strengthen the joint. The tworails are pressed together after the molten mass has been cast into themolds, so that a sufficient heat has been delivered to the parts to bewelded. According to tests it has been found that one and one-halfminutes suffice for heating the rails sufficiently for welding the same.

After the process has been carried out in the above-described way themolds are taken 01% and the alumina coating is knocked off, so that arail is obtained, as shown in Fig. 3, in which figure a is therail-fish, and g is a knob formed in 0 by the overflowing metal, whichknob is afterward also knocked off.

In the modification shown in Fig. 4 two separate openings e e for thealumina and the iron are provided. Through the opening 6 the alumina andthrough c the molten iron is cast into the molds. The process is carriedout in the same way as described above.

In Fig. 5 a mold is shown consisting of two parts separated in line on1%, so that on one side 7* of the rails the alumina and on the otherside r of the rails the iron is cast. The rail-fisht would be arrangedin this case only on one side of the rails and would extend to a certainheight 9'.

The process may be carried out also in another way. The top mold in Fig.1 might be enlarged so as to receive the whole mass, consistingof themolten alumina and the iron. Then a hole is punched through the bottomIt is advantageous to fill the cruof this mold, whereby the molten ironflows through this hole around the lower part of the rails. t

Another form of arrangement is shown in Fig. 6, in which the two moldsare not arranged one above the other, but one mold 00 at the side of theother one 2 the molds not touching each other, but being perfectlyseparated and leaving a space of about one-half inch between the same.Into this free space .2 between the two molds the molten iron is cast upto a certain height h, whereas in the two molds the liquid alumina iscast. The heating of the welding-face will be obtained by the conductionof the heat transferred to the rails by the alumina.

The most practical form of carrying the process into effect isillustrated in Figs. 7, 8, and 9. In these figures 1 is a mold. 2 is acrucible situated above the same and provided with a tap-hole 3, whichtap-hole may be closed by means of a plug or, as shown in the drawings,by means of a plate 10, consisting of sheet-iron, asbestos, or the like.6 is the reaction mass. iare the rails to be joined. As will be seenfrom the drawings, the eru- .cible is situated so that the tap-hole 3 isnot situated vertically above the head of the rail. If the reaction mass6 is ignited, the highlyoverheated metal 7, Fig. 8, melts the plate 10and flows into the space 5 of the mold 1 and from there around the footof the rail, as may be seen from the drawings, the alumina 8 flowing outafter the metal flows around the upper part of the rail, as Will be seenfrom Fig. 9. It will be understood that instead of arranging a specialcrucible above the mold this mold may be provided with a' funnel 12 onits top, in which funnel the mixture can be filled.

Contrary to the known process consisting in casting metals around thelower part of the rails by the process described above a better weldingor joining of the metal cast around the rail-foot with this rail-foot isattained by the high superheat of the metal, whereby it is attained thatthe joining faces are joined in that way that one continuous metal pieceis formed.

Having thus fully described the nature of my said invention, what Idesire to secure by Letters Patent of the United States is 1. Process ofjoining metals by means of the heat arising by the reaction taking placewhen pulverized aluminium and oxygen containing metal compounds aremixed and this mixture is ignited, said process consisting in castingthe highly-overheated molten metal arising by the reaction directlyaround one part of the metal pieces to be joined, and the molten aluminaaround another part of these metal pieces, substantially as describedand for the purpose set forth.

2. Process of joining metal pieces, consisting in surrounding the endsto be joined with the mold, filling this mold partly withhighlyoverheated molten metal and partly with mol- I ten aluminasubstantially as described and for the purposeset forth.

3; Process of joining metal pieces consisting in surrounding the ends tobe joined with a mold filling a crucible provided with a taphole in thebottom, with a mixture consisting of aluminium and an oxygen-containingmetal compound, bringing the crucible above the mold in that Way thatthe tap-hole is not situated vertically above the parts to be joined,igniting the mixture contained in the crucible and opening the tap-holeof the same, substantially as described and for the purpose set forth.

4. Process of joining metal pieces consisting in surrounding the ends tobe joined with a mold filling a crucible provided with a taphole in thebottom, with a mixture consisting of aluminium and an oxygen-containingmetal compound, after the tap-hole being closed by means of a substancecapable of being moiten by the heat arising by the reaction taking placeby the ignition of the mixture mentioned above, bringing the crucibleabove the mold in that way that the tap-hole is not situated verticallyabove the metal pieces to be joined and igniting the mixture containedin the crucible, substantially as described and for the purpose setforth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HANS GOLDSOHMIDT.

Witnesses WILLIAM ESSENWEIN, PETER LIEBER.

